At this stage, I think Walt is irredeemable. I don't think there's anything he can do to make things right. He's lost everyone and everything, and I don't see any way for him to win back his family, who are just about all he could conceivably have left. We know he's going to pick up some serious artillery, presumably to take some revenge on someone, but all that means is that he is yet to lose something more that will force him to do that, which means his family are probably in trouble. If they kill Holly, it's totally on, but that would be going way off the deep end because killing kids on TV shows or in films does not go over well with audiences...
Jesse could come good by the end of this. He's utterly desperate, so it wouldn't be out of the question for him to do something crazy to get out of the mess he's in, and he's still got someone to save in Brock. He can still win.